FIG. 1.

(A) Structure and expression of CD4A/HIV^WT and CD4C/HIV^WT transgenes. The enhancer fragment of the mouse CD4 gene (mCD4 enh.) (vertically hatched bar), the human CD4 promoter (hCD4C prom.) (white bars and boxes), the HIV-1 pNL4-3 DNA fragment (diagonally hatched bars and boxes), simian virus 40 (SV40) polyadenylation sequences (black boxes), and the HIV-1 fragments cloned in GEM-4 (Promega) and used for riboprobes (lower white bars) are illustrated. Restriction sites: A, AatII; Bs, BssHII, S, SacI. (B and C) Transgene RNA expression in CD4A/HIV^WT and CD4C/HIV^WT mice. Northern blot analysis was carried out on total RNAs (10 μg) extracted from different organs of CD4A/HIV^WT mice (from lines F22200, F22194, and F22410) (B) or CD4C/HIV^WT mice (from lines F17018, F17001, and F17086) (C). K, kidney; Ln, lymph node; Th, thymus; Lu, lung; S, spleen; Lv, liver: Mu, muscle; He, heart; Br, brain; Mgl, mammary gland of a mouse mammary tumor virus/HIV Tg mouse (28) used as a positive control. Hybridization was performed with a ³²P-labeled 8.9-kbp SacI fragment from the HIV-1 genomic sequences. The filters were then washed and rehybridized with an actin probe.